Conventionally, a laminated iron core was typically manufactured by processing a sheet steel strip made of electromagnetic steel by using a progressive metallic die machine. In a progressive metallic die machine, locating holes, slots and internal teeth are punched out in a sheet metal strip in a sequential manner so as to form various parts of each iron core laminate, and a prescribed number of blanked iron core laminates are stacked and bonded to one other. The bonding of iron core laminates may be accomplished by various methods such as the lamination crimping method in which irregularities for crimping purpose are formed in each iron core laminate, and the iron core laminates are crimped to one another by compressing together the iron core laminates as they are stacked one over another, and the lamination welding method in which iron core laminates are stacked, and then laser welded to one another. However, as these methods tend to cause impairment of the magnetic property of the bonded parts, the lamination bonding method is widely selected. In the lamination bonding method, an adhesive agent is applied to a surface of a sheet metal strip, and the iron core laminates that are blanked from the sheet metal strip are bonded together as they are stacked up in a progressive metallic die machine. See Patent Documents 1 and 2.
A known adhesive agent supply unit that is used for implementing the lamination bonding method includes a cylinder retained by a lower metallic die assembly in a press forming machine in a vertically slidable manner, a plurality of adhesive agent transferring nozzles provided at the free end of the cylinder, a storage chamber defined in a free end part of the cylinder to store the adhesive agent supplied via an adhesive agent supply passage at a prescribed pressure, and a piston slidably received in the cylinder for pushing out the adhesive agent in the storage chamber toward the transferring nozzles. As the upper metallic die assembly of the press forming machine is lowered, and the free end of the cylinder is pushed down by the upper metallic die assembly, the piston is caused to move upward relative to the cylinder with the result that the adhesive agent is ejected from the transferring nozzles onto the iron core laminate. See Patent Document 3.